Oil leaking from head gasket? To me, that's odd....and almost impossible. Probably coming from valve cover gasket or some other place. Double check that leak.
Don't really have any comments or suggestions until you have issues. Leaks on old trucks are common. As said, you have a SBC.

The Chevy fender emblem is 1959 but the truck seems to be a 55-56. Not sure. The "S" in the serial number can indicate 58-59 BUT the axle numbers vs 270 motor vs 370 series, don't seem to be found in 58-59.


Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn